PCI: remove useless pci driver method

Remove pointless and never-called enable_wake() hook from pci_driver and
from documentation.  Evidently this was introduced in the 2.4.6 kernel,
but there's no evidence it was ever called; and it was rarely implemented.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/power/pci.txt

@@ -164,7 +164,6 @@ struct pci_driver:
 
         int  (*suspend) (struct pci_dev *dev, pm_message_t state);
         int  (*resume) (struct pci_dev *dev);
-        int  (*enable_wake) (struct pci_dev *dev, pci_power_t state, int enable);
 
 
 suspend
@@ -251,42 +250,6 @@ The driver should update the current_state field in its pci_dev structure in
 this function, except for PM-capable devices when pci_set_power_state is used.
 
 
-enable_wake
------------
-
-Usage:
-
-if (dev->driver && dev->driver->enable_wake)
-	dev->driver->enable_wake(dev,state,enable);
-
-This callback is generally only relevant for devices that support the PCI PM
-spec and have the ability to generate a PME# (Power Management Event Signal)
-to wake the system up. (However, it is possible that a device may support 
-some non-standard way of generating a wake event on sleep.)
-
-Bits 15:11 of the PMC (Power Mgmt Capabilities) Register in a device's
-PM Capabilities describe what power states the device supports generating a 
-wake event from:
-
-+------------------+
-|  Bit  |  State   |
-+------------------+
-|  11   |   D0     |
-|  12   |   D1     |
-|  13   |   D2     |
-|  14   |   D3hot  |
-|  15   |   D3cold |
-+------------------+
-
-A device can use this to enable wake events:
-
-	 pci_enable_wake(dev,state,enable);
-
-Note that to enable PME# from D3cold, a value of 4 should be passed to 
-pci_enable_wake (since it uses an index into a bitmask). If a driver gets
-a request to enable wake events from D3, two calls should be made to 
-pci_enable_wake (one for both D3hot and D3cold).
-
 
 A reference implementation
 -------------------------